4. Storms . 



The area is affected by both extratropical (northeasters) and tropical 

 (hurricanes) cyclones. Bosserman and Dolan (1968), who examined the intensity 

 and frequency of extraptropical storms affecting North Carolina, classified 

 857 storms according to the 10 tracks shown in Figure 20; note that seven of 

 the tracks pass the FRF site. The most damaging storms follow the three 

 widest arrows (2, 3, and 4). The severest situation occurs when the movement 

 of a track 2 storm is slowed by a blocking high-pressure system to the north. 

 This occurred during the Great East Coast Storm of March 1962 and resulted in 

 strong northeasterly winds of long duration over a long fetch. 



Figure 20. Storm tracks affecting the east coast 

 (from Basserman and Dolan, 1968). 



Storm occurrence prediction is somewhat difficult since cyclogenesis 

 (storm formation) frequently occurs offshore of Cape Hatteras. Bosserman and 

 Dolan (1968) found that about 19 percent of all storms affecting the Outer 

 Banks develop in this manner. They also hindcasted wave heights for each 

 storm studied. Storm frequencies (all tracks) by wave height and month are 

 summarized in Table 7 and are shown in Figure 21. 



Between 1901 and 1926, 31 hurricanes at full strength made either landfall 

 along coastal North Carolina or passed close enough to affect the area (Baker, 

 1978). The frequency of occurrence of these hurricanes varies considerably 

 (Fig. 22). The area between Cape Ilatteras and Cape Lookout has the highest 

 hurricane occurrence while the area around the FRF has the lowest with a 

 hurricane reaching the area once every 42 years. Tracks of historic hurri- 

 canes passing within 50 nautical miles (90 kilometers) of the FRF are shown in 

 Figure 23 (Ho and Tracey, 1975). 



44 



